• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Near Threatened	C1+2a(i)
2016	Vulnerable	B1ab(i,ii,iii,v);C2a(i)
2012	Vulnerable	B1ab(i,ii,iii,v);C2a(i)
2008	Vulnerable	B1a+b(i,ii,iii); C2a(i)
2004	Vulnerable
2002	Vulnerable
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type	continent	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	43,800 km2	medium
Area of Occupancy (breeding/resident)	9,680 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	4200-13000 mature individuals	poor	inferred	2023
Population trend	decreasing	poor	suspected	2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	2.57 years	-	-	-
Number of subpopulations	10-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The population size has not been quantified, but the species is described as locally common (Zimmer et al. 2020). Assuming that the species occurs at the same density as two congeners (H. stictocephalus and H. sticturus: 2-5 mature individuals/km²; Santini et al. 2018), and assuming that 50% of forests within the range are occupied (i.e., 2,100-2,600 km²; Global Forest Watch 2022), the population may number 4,200-13,000 mature individuals.

Trend justification: There are no data on the population trend, but due to the species' specific habitat requirements declines are suspected on the basis of ongoing forest loss and degradation.
Over ten years, 9% of tree cover is lost within the range (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). As the species has limited dispersal abilities and is confined to small, isolated subpopulations in disjunct patches of restinga forest (ICMBio 2018), population declines may be steeper than the rate of tree cover loss suggests due to increasing fragmentation between occupied patches. Tentatively, population declines are here placed in the band 10-19% over ten years.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Brazil	extant	native	yes

Country/Territory	IBA Name
Brazil	Estação Veracruz
Brazil	Foz dos Rios Pardo e Jequitinhonha and Santa Cruz Cabrália / Belmonte
Brazil	Ilhéus / Itabuna
Brazil	Parque Nacional do Pau Brasil / Trancoso

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	resident
Savanna	Dry	major	resident
Altitude	0 - 840 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Livestock farming & ranching - Agro-industry grazing, ranching or farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Bahia Antwren Herpsilochmus pileatus. Downloaded from https://datazone.birdlife.org/species/factsheet/bahia-antwren-herpsilochmus-pileatus on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/11/2024.